1. Technical Field
Embodiments discussed herein relate to a conveying device or an image forming apparatus, and in particular, to a conveying device and an image forming apparatus capable of conveying a sheet absorbed with an electric charge.
2. Related Art
As an image forming apparatus, such as a printer, a facsimile machine, a copier, a plotter, a multifunctional machine combining these capabilities, etc., an ink-jet printer that employs a droplet ejecting-type printing system with a droplet discharging head that ejects the droplet is known.
In such an image forming apparatus, a droplet having landed on a printing medium takes a long time to dry and form an image thereon. For this reason, the printing medium is conveyed with its image forming surface distanced from (i.e., not contacting) a sheet conveying device until the droplet on the printing medium dries.
Certain known conveying systems convey the printing medium using electrostatic force generated in a sheet conveying device to attract the printing medium.
However, it is not possible to apply an electric charge of a required quantity on the conveying member for the generation of electrostatic force, when the environment changes, especially in low-temperature and low-humidity environments.
In detail, to increase the charge quantity on the conveying member, it is necessary to increase the applied voltage or the applied current. However, increasing the applied voltage causes damage to the conveying member by spark discharge from a charging unit. Moreover, reducing the resistance of the charging unit to increase the applied current causes generation of unstable potential to the conveying member.